The majority of dust collectors are based on filter technology with a filter medium consisting of socks, or folded cartridge filters, usually integrated in a container with an inlet similar to a cyclone inlet.
The disadvantage of the filter technology is that in the presence of a moderate amount of dust, the pressure drop of the dust collector increases and the suction force decreases. This disadvantage creates a need for additional maintenance of the dust collector. For example, concrete grinding requires that all of the abrasive residue be removed before the next grinding cycle. Existing methods for filter cleaning requires releasing the vacuum several times in succession, by opening a relief valve. This cleaning procedure leads to long working shifts and low productivity.
Traditional cyclones with a characteristic conical bottom have not been able to replace hose and cartridge filters because of a poor separation capability, especially for dust particles below 5 microns.